another exhaust log to center riser question

[steves86ta]

Hi Guys,
Im sorry to bring this up again i have been searching for days, but still am having a hard time getting my questions answered.

I just picked up two exhaust manifolds for a Great price. They are the center riser manifolds by mercruiser.

My current configuration is a bone stock 1980 Mercruiser 228 with the stock logs (which are cracked and leaking)

I can and will take pictures tonight if need-be.

My questions are, what is involved to add these newer style center riser style manifolds as far as the cooling system goes.

I have read that i may or may not need a new thermostat housing. I already need to replace the hoses and plan on doing that so if i need custom hoses that is fine. I really dont want to spend 300 on a thermostat housing if my stock one can be plumbed to work correctly.

Does anyone have a picture or diagram that i can use? Or am i SOL and need to buy a new housing?

Is it possible to get rid of the "warm water" cooling and run straight cold water from the outdrive?

Any other suggestiosn or tips will be very appreciated.

I appreciate your time

thank you
Steve

 

[Bondo]

Re: another exhaust log to center riser question

Ayuh,.... Welcome Aboard Steve,.... Ya,.... yer SoL, the T-stat is Necessary, 'n the Right housin' is too...

 

[steves86ta]

Re: another exhaust log to center riser question

Ayuh,.... Welcome Aboard Steve,.... Ya,.... yer SoL, the T-stat is Necessary, 'n the Right housin' is too...

Do you happen to have a part number or by chance a link to the right housing?

Thanks
Steve

 

[steves86ta]

Re: another exhaust log to center riser question

would something along these lines work?
Thermostat Housing Kit | Cooling Systems | MonsterMarineStore.com

 

[Cresco750]

Re: another exhaust log to center riser question

I converted my 228 to centre riser manifold from log style a few months back. Yes, you do need the thermostat. There are variations in the t-stat housing which may affect the way yours is ultimately plumbed, but I managed to reuse the existing hoses (or at least replaced them with some NOS ones that came with the boat), but found that the engine would not come up to temperature. I later discovered that the place that supplied my the manifolds and elbows etc neglected to supply me the stainless steel block off plate that goes between manifold and riser. Put this in and she's all hunky-dory.
Also, I discovered that a number of accessories mounted off the old log manifolds, such as alternator, fuel pump, starter solenoid, etc, so I ended up having to make new places for these to mount (new mounts are available for some of these which will go onto the new style manifolds, but aren't necessarily included unless you buy a full conversion kit).
Post a photo of your t-stat housing and I'll see if its the same as mine.

 

[steves86ta]

Re: another exhaust log to center riser question

I converted my 228 to centre riser manifold from log style a few months back. Yes, you do need the thermostat. There are variations in the t-stat housing which may affect the way yours is ultimately plumbed, but I managed to reuse the existing hoses (or at least replaced them with some NOS ones that came with the boat), but found that the engine would not come up to temperature. I later discovered that the place that supplied my the manifolds and elbows etc neglected to supply me the stainless steel block off plate that goes between manifold and riser. Put this in and she's all hunky-dory.
Also, I discovered that a number of accessories mounted off the old log manifolds, such as alternator, fuel pump, starter solenoid, etc, so I ended up having to make new places for these to mount (new mounts are available for some of these which will go onto the new style manifolds, but aren't necessarily included unless you buy a full conversion kit).
Post a photo of your t-stat housing and I'll see if its the same as mine.

Thanks for the info, in my situation it appears that i will just need to move the Alternator to a "low mount" passenger side auto mount.

My fuel separator is going to be replaced by a stand alone unit since i will be changing the entire fuel system anyway.

If i understand correctly, all i really need is a new thermostat hosing and a seperator plate for the manifolds?

If so will any thermostat housing work? or do i have to buy an insanely expensive mercruiser unit?

Here is a picture of my current setup:

PS
I found this picture on here, i was wondering if i routed my hoses like this if it would work? Would i still need the block off plate? It appears that i can "loop" the stock thermostat but i dont know for sure

Thank you for any insight you can provide

 

[Cresco750]

Re: another exhaust log to center riser question

That's the same t-stat housing as mine, which you will be able to reuse. No need to loop the pipe work back, assuming you will be using raw water cooling, but you will need to hook a pipe into the front plug of the exhaust elbow in order for the cooling water to dump when the thermostat is closed. Basically, I just studied the way the hoses were hooked to the log set up and did same with new system, ie the front hose went to the front of the manifold, rear to rear, elbow to elbow (will need to be shortened).

 

[steves86ta]

Re: another exhaust log to center riser question

That's the same t-stat housing as mine, which you will be able to reuse. No need to loop the pipe work back, assuming you will be using raw water cooling, but you will need to hook a pipe into the front plug of the exhaust elbow in order for the cooling water to dump when the thermostat is closed. Basically, I just studied the way the hoses were hooked to the log set up and did same with new system, ie the front hose went to the front of the manifold, rear to rear, elbow to elbow (will need to be shortened).

Hi Cresco,
Thanks for the info. The hoses needing to be changed are not a big deal to me. I can buy new hose.
Could you please if you dont mind get me a picture or two of how yours is setup? Ive been looking at diagrams for days and i cant place it. I would really appreciate it.

That is great news about the thermostat housing. I was on the fence about just selling the manifolds.

Thanks again!

 

[Cresco750]

Re: another exhaust log to center riser question

Will do. Sorry I don't think I've got any on the computer but I'll try get down to the boat today or tomorrow a d take one for you (sorry if I'm a bit slow in getting one - new baby in the house!)

 

[steves86ta]

Re: another exhaust log to center riser question

Will do. Sorry I don't think I've got any on the computer but I'll try get down to the boat today or tomorrow a d take one for you (sorry if I'm a bit slow in getting one - new baby in the house!)

Congratulations on the baby!!! Take your time i still have a while before this goes in i just dont like surprises

 

[steves86ta]

Re: another exhaust log to center riser question

Will do. Sorry I don't think I've got any on the computer but I'll try get down to the boat today or tomorrow a d take one for you (sorry if I'm a bit slow in getting one - new baby in the house!)

Cresco,
Sorry for the additional question. But i was wondering about this blockoff plate you are talking about.

What exactly does it do? Just block the water from going up into the elbow? so that it can recirculate in the manifold?

My manifolds are the "dry-joint" style so if i understand correctly i just need a plate to block the water from running into the elbow, if so this wont be a huge problem. And i may still go this route.

Thanks again

 

[Cresco750]

Re: another exhaust log to center riser question



Thanks. Don't tell my wife but I swung by the boat on the way to picking her up from the hospital and took a photo

My manifolds are the regular non-dry joint style so I'm not sure how the plumbing will differ on your setup, but as you can see in the photo I installed 90deg brass elbows in the front and rear of the manifold and reused a straight fitting from the old manifolds for the new exhaust elbow. Plumbing should be obvious from the pic, but again yours may have to be slightly different.
The block off plate does exactly as you described; it redirects the flow back through the block rather than dumping straight overboard, but with dry joint you wouldn't be needing this, but perhaps some sort of restricter plate to reduce the flow from manifold fitting to elbow fitting?

Cheers

 

[steves86ta]

Re: another exhaust log to center riser question

View attachment 193107

Thanks. Don't tell my wife but I swung by the boat on the way to picking her up from the hospital and took a photo

My manifolds are the regular non-dry joint style so I'm not sure how the plumbing will differ on your setup, but as you can see in the photo I installed 90deg brass elbows in the front and rear of the manifold and reused a straight fitting from the old manifolds for the new exhaust elbow. Plumbing should be obvious from the pic, but again yours may have to be slightly different.
The block off plate does exactly as you described; it redirects the flow back through the block rather than dumping straight overboard, but with dry joint you wouldn't be needing this, but perhaps some sort of restricter plate to reduce the flow from manifold fitting to elbow fitting?

Cheers

cresco
thanks a lot for the picture! you helped me make up my mind to keep the manifolds. I plan to document the entire process and make a thread for future people

Thanks again!
Steve

 

[Cresco750]

Re: another exhaust log to center riser question

No problem! Just do a little more research re the compatibility of your t-stat housing and dry joint manifolds; I have the feeling that they may have different requirements (sorry, I have no experience with them), but hopefully someone here should be able to advise?

Cheers

 

[steves86ta]

Re: another exhaust log to center riser question

No problem! Just do a little more research re the compatibility of your t-stat housing and dry joint manifolds; I have the feeling that they may have different requirements (sorry, I have no experience with them), but hopefully someone here should be able to advise?

Cheers

I think they will be the same as yours from what i have found. I just need to order the "block" off plates for this style of manifold. I have a digital temperature gun so i can keep an eye on it

thanks again!
Steve

 

[achris]

Re: another exhaust log to center riser question

Hi Steve, I've come in here a little late, but I have a couple of questions. One... Are you still running raw water cooling or have you changed to closed cooling. Two... What's 'warm water cooling'? (the one you want to get rid of)

If you have bought dry-joint manifolds and elbows, then the set up on Cresco's is not going to be the same as yours. You may need to use resistor gaskets between manifold and elbow, and the hosing will have to be set up right. Give me some time and I'll weed through the flow diagrams for your original set up and the new set up... See if I can come up with something that will work. Just bear in mind that standard manifolds and elbows are VERY different (in flow requirement) to dry-joint.

Chris......

 

[achris]

Re: another exhaust log to center riser question

Here's what I've come up with... See how it sounds...


Let’s start with the standard set up. You have 6 hoses attached to the thermostat housing and 2 hoses on the thermostat cover.

The original set up considered the manifolds as part of the engine as far as water circulation goes. We need to modify that. The dry joint manifolds have water static in them until the thermostat opens, then the hot water runs into the bottom of them and up through the restrictor gasket and elbow, then out (to the exhaust pipe). This is called a ‘warm manifold’ set up.

The easiest way we are going to do this utilizing your existing thermostat housing is to completely change the way it currently works... and give you ‘cold manifolds’.

I suggest looping the 2 hoses that go to each manifold. Take the 2 hoses that run from the thermostat cover and run them to the bottom of the dry-joint manifolds. Put full flow gaskets between manifolds and elbows and plug the fitting at the front of the elbows. (or replace it with a blank) ....

With that set up you will have cold manifolds... ie When the thermostat is closed, cold water not going to the engine will go through the manifolds and then up to the elbows and out. When the thermostat opens the hot water from the engine will go through the manifolds and new, cold water from the drive will go into the engine....

If you want to retain the 'warm manifold' set up, then let me know and I can give you the set up for that...

Cheers,

Chris......

 

[steves86ta]

Re: another exhaust log to center riser question

Hi Steve, I've come in here a little late, but I have a couple of questions. One... Are you still running raw water cooling or have you changed to closed cooling. Two... What's 'warm water cooling'? (the one you want to get rid of)

If you have bought dry-joint manifolds and elbows, then the set up on Cresco's is not going to be the same as yours. You may need to use resistor gaskets between manifold and elbow, and the hosing will have to be set up right. Give me some time and I'll weed through the flow diagrams for your original set up and the new set up... See if I can come up with something that will work. Just bear in mind that standard manifolds and elbows are VERY different (in flow requirement) to dry-joint.

Chris......

HI Chris,
Thanks for popping in, ill try to answer your questions the best i can since i am new to boats in general not autos.

1. If by "Raw Water Cooling" you mean lake or sea water then yes, my idea for the drive to suck up the water and cool the engine
2. I guess by "Warm Water" i mean using the exhaust manifolds as an extension of the block, so the water is not straight from the body of water, im not sure if it even makes sense.

I did purchase "dry-joint" manifolds, i will make a diagram and post it here to see if my understanding will work.

thanks again!
Steve

 

[steves86ta]

Re: another exhaust log to center riser question

Here's what I've come up with... See how it sounds...


Let’s start with the standard set up. You have 6 hoses attached to the thermostat housing and 2 hoses on the thermostat cover.

The original set up considered the manifolds as part of the engine as far as water circulation goes. We need to modify that. The dry joint manifolds have water static in them until the thermostat opens, then the hot water runs into the bottom of them and up through the restrictor gasket and elbow, then out (to the exhaust pipe). This is called a ‘warm manifold’ set up.

The easiest way we are going to do this utilizing your existing thermostat housing is to completely change the way it currently works... and give you ‘cold manifolds’.

I suggest looping the 2 hoses that go to each manifold. Take the 2 hoses that run from the thermostat cover and run them to the bottom of the dry-joint manifolds. Put full flow gaskets between manifolds and elbows and plug the fitting at the front of the elbows. (or replace it with a blank) ....

With that set up you will have cold manifolds... ie When the thermostat is closed, cold water not going to the engine will go through the manifolds and then up to the elbows and out. When the thermostat opens the hot water from the engine will go through the manifolds and new, cold water from the drive will go into the engine....

If you want to retain the 'warm manifold' set up, then let me know and I can give you the set up for that...

Cheers,

Chris......

Here's what I've come up with... See how it sounds...


Let’s start with the standard set up. You have 6 hoses attached to the thermostat housing and 2 hoses on the thermostat cover.

The original set up considered the manifolds as part of the engine as far as water circulation goes. We need to modify that. The dry joint manifolds have water static in them until the thermostat opens, then the hot water runs into the bottom of them and up through the restrictor gasket and elbow, then out (to the exhaust pipe). This is called a ‘warm manifold’ set up.

The easiest way we are going to do this utilizing your existing thermostat housing is to completely change the way it currently works... and give you ‘cold manifolds’.

I suggest looping the 2 hoses that go to each manifold. Take the 2 hoses that run from the thermostat cover and run them to the bottom of the dry-joint manifolds. Put full flow gaskets between manifolds and elbows and plug the fitting at the front of the elbows. (or replace it with a blank) ....

With that set up you will have cold manifolds... ie When the thermostat is closed, cold water not going to the engine will go through the manifolds and then up to the elbows and out. When the thermostat opens the hot water from the engine will go through the manifolds and new, cold water from the drive will go into the engine....

If you want to retain the 'warm manifold' set up, then let me know and I can give you the set up for that...

Cheers,

Chris......

HI Chris,

Here are some Diagrams, can you please take a look and try to not hate my Paint work too much ;-)

Here is how i understand the Stock cooling system to work. Blue means cold fresh water from the lake picked up from the drive, Green is "warmed" coolant, and red is the Hot coolant that will go overboard

Here is how i plan to setup the center riser manifolds, And i will buy the block off plate to keep the water in the manifold seperate from the riser (** Warning, awesome paint skills**)

Does this sound right? Does it look like it will work?

thanks again!
Steve

 

[achris]

Re: another exhaust log to center riser question

Steve, Why you use Ford engine diagrams. You have a GM... And the thermostat housing is quite different.... Find the drawing for 228 and have another try...

Chris.....